Work package 06

Adaptive image-guided modulated radiotherapy

Objectives During the treatment course, the tumour and normal tissues are variable with respect to both size, shape and positions. The purpose of this work package is to investigate the potential of adapting treatment plans with regard to the changing patient anatomy during the course of treatment, based on in-room imaging strategies for complex treatment modalities including IMRT, modulated arc therapy, and other dynamic treatments. The work package will primarily include studies for head-and-neck, lung and pelvic cancers.Description of workTask 6.1. Volumetric in-room imaging for treatment planning. Development of in-room imaging techniques for organ delineation and dose calculation. Delineation of target volumes and organs at risk (OAR) will be investigated, specifically for auto-segmentation, assigning Hounsfield Units (HU) in conebeam CT (CBCT) scans for dose calculation, and accumulation of dose for consecutive scans. Task 6.2. Plan-of-the-day. Practical implementation of the concept of replanning a treatment on a daily basis with daily imaging. This includes the consideration of and trade-off between dose limits to targets and OAR, the possibility of shrinking fields for shrinking targets, inverse optimization on a daily basis on volumetric scans, online versus offline strategies for replanning, and the possibility of daily dose painting. Task 6.3. Volumetric arc therapies. Dose calculations and dose measurements for highly complex intensity modulated arc therapies. Investigations will be carried out for optimisation of treatment plans, high precision Monte Carlo simulations of dose delivery, time resolved dosimetry, absolute dosimetry, cost-effectiveness analysis, and comparison to other modulated therapy strategies (IMRT). There is a collaboration with departments in Bellinzona (Bellinz) and Vrije Universitet Amsterdam (VUA).Deliverables (projected outcome)D6. The outcome of this work package will be a set of tools to enable the full scope of utilizing daily image guidance to perform modulated dose delivery to a changing anatomy, ranging from daily volumetric imaging, and it’s use for replanning treatment, to the delivery of complex modulated beams. Treatment individualized not only to each patient before treatment, but including the individual anatomic changes during treatment, will facilitate dose escalation to the tumour and reduction of healthy tissue irradiation.